Existing locking mechanisms such as strikes, locks, and rim exit devices incorporate mechanisms that use some type of locking element such as a keeper, a latch bolt, or a pullman style latch bolt. In unlocking, the locking element (referred to generically herein as a “latch”) is required to rotate or retract out of the way of the mating locking element to reach a state of being unlocked. The latch may be mounted in a door and the mating locking element (referred to herein generically as a “strike” or “strike plate”) may be mounted on a door frame, or vice versa, to equal effect.
Emergency exit doors typically employ what is commonly referred to as a panic bar to enable actuation of the locking mechanism so as to enable door opening. Panic bars allow users to open the door without necessarily requiring the use of their hands. Rather, the user's body can be used to push against the panic bar until the latch is retracted from the striker. Alternatively and additionally, exits doors may also include provision of an electrically actuable locking device such that, upon initiation, an electric current is supplied to the latch to withdraw the latch from the strike.
For electrified rim exit devices, such as those which utilize a panic bar, unlocking is typically achieved by utilizing an electromechanical device actuated by a solenoid or motor, to draw a pullman-style latch bolt out of or away from the strike to release the locked door. These electromechanical devices are typically very large in size, require numerous interconnected moving parts, are aesthetically unpleasing and require a large amount of power or current to actuate the unlocking mechanism.
What is needed in the art is a simplified locking device, and especially a simplified locking device that can fit within a limited amount of functional space but still meet the force requirements, either electrical or manual, of a design that has moving parts and some degree of complexity to resist easy defeat.
It is a principal object of the present invention to provide a compact locking device having simplified actuation of the latch to permit opening of the door, as well as securing the latch from unauthorized actuation when the latch resides with the strike.